How do you make better development decisions faster?

Dermal Absorption

Designing and performing GLP-compliant dermal absorption studies require a deep understanding of the unique characteristics of topical drug delivery systems and related OECD Guidelines.  EAG scientists have years of expertise in helping pharmaceutical manufacturers evaluate skin absorption through both In vitro and in vivo skin disposition studies.

EAG offers testing outlined in OECD 427 (in vivo studies in rodent models) and OECD 428 (in vitro studies using human and animal skin), which are often performed in parallel to predict dermal absorption in humans (sometimes called “the triple pack” or “parallelogram” approach.)

Our scientists employ a variety of custom made diffusion cells that can be used for dermal absorption studies with complex products.  This includes trapping devices for mass balance recovery of volatile chemicals.

Also known as percutaneous absorption, we perform these studies with 14C radiolabeled or non-radiolabeled test substances in a variety of formulations including solids, dusts, solutions, suspensions and vapor exposures.

  • Skin Pharmacodynamic Studies: In vitro and in vivo skin disposition studies including evaporation, deposition, percutaneous penetration, and metabolism analysis. Development of model systems for membrane transport and release studies. In Vivo studies are performed in collaboration with a partner laboratory that complies with our rigorous quality standards.
  • Analytical Support: Radiometric analysis of 14C, 3H and 35S isotopes by liquid scintillation counting; combustion/LSC for solid matrices; chromatographic analysis using HPLC or TLC with radioisotope detection including flow-through radioisotope detection or phosphor imaging; HPLC, LC-MS, GC and GC-MS chemical analysis. Additionally, EAG offers analysis of metals using ICP-OES and ICP-MS.
  • Formulation: Formulation of test substance including topical new drug, OTC pharmaceutical and cosmetic products
  • Specification Development: Quality control release specification development of raw materials and formulated products
  • Manufacturing Process Development: Scale-up and manufacturing methods development for new products
  • Stability Testing Protocols and Evaluation: Development of stability testing protocols and evaluation of testing results
  • Radiolabeling & Custom Synthesis: In-house radiolabeling expertise add the convenience of streamlined study execution and seamless project management

Bill Reifenrath, Ph.D., EAG Laboratories Senior Scientific Advisor 

Having been involved in early research that helped establish test guidelines in the 1990’s, Dr. Reifenrath is a pioneer in the development and refinement of dermal absorption techniques used to screen topical pharmaceuticals and evaluate dermal absorption of chemicals for risk assessments.   In 1994, he founded Stratacor, a contract research organization specializing in skin toxicology and pharmacology.   Dr. Reifenrath is an active member of the Society of Toxicology (SOT) and previously served as Councilor and President of SOT’s Dermal Toxicology Specialty Section.